Boiler



2 Sheets-Sheet 1.

no Model.) L'. SAUNDERS..

BOILER.

No. 550,846 Patented Dec. 3, 1895.

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ANDREW B.GRAHAM, PMOTOLHNQWASNINGTUNDC.

kn w (No Model.)-

L. SAUNDERS.

BOILER.

No. 550,846. PatentedDec. 3,1895.

AN DREW B.GRAHAM.PHO'I'OUTHQWASHINGION, 0.6,

TJNrTED STATES PATENT OFFI E.

' LEWIS SAUNDERS, vOF LAWRENCE,MASSACHUSETTS.

BOILER.

SPECIFICATION forming part of Letters Patent No. 550,846, dated December 3, 1895.

Application filed January 5 1894.

To all whom it may concern:

Be it known that I, LEwIs SAUNDERS, of Lawrence, in the county of Essex, State of Massachusetts, have invented. certain new and useful Improvements in Boilers, of which the following is a description sufficiently full, clear, and exact to enable any person skilled in the art or science to which said invention appertains to make and use the same, referenee being had to the accompanying drawings, forming part of this specificatioi'i, in which-- Figure 1 is a rear elevation of my improved boiler; Fig. 2, a side elevation of the same; Fig. 3, a top plan view, and Fig. i a vertical section through the tubes.

Like letters and figures of reference indicate corresponding parts in the different figures of the drawings.

My invention relates especially to a vertical tubular boiler wherein by a peculiar arrangement of parts I am enabled to obtain an extended heating-surface with greatly decreased cost of construction and to effect a considerable saving of fuel.

In the drawings, A represents the reetan gular fire-box, provided in its forward end with the ordinary door b. Two series of vertically-arranged circulation} tubes O C are disposed in parallelism and secured by their lower ends in the fire-box over the grate. A central series of tubes D are arranged between the series 0 O and are elongatedto project above said tubes, their upper ends forming a steam-chest. The tubes are formed of light material, and cap-heads f are welded thereon. These heads may be screwed onto the bodies of the tubes, if preferred. Flues g connect the heads of the tubes C C and open there through.

Pendent from the upper heads f of the central tubes D there are perforated tubes 72 of the form shown and described in WV. B. Fowlers United States Letters Patent, No. 483,000, granted September 20, 1892. The upper ends of the tubes are closed and their lower ends are also elosedby acap f These pendent tubes are provided with perforations inear their upper and lower ends, respectively, and serve to create circulation throughout the main cylinders D. Condensation of steam in the chest or upper ends of the tubes threaded into the tubes.

Serial No. 495,857. (No model.)

D. entersthe perforations 2' and descends in ties. It furthermore renders the steam much drier in theupper portions of the tubes D.

Each tube D isjconnected at its upper and lower ends by duets 7t, arranged horizontally and entering through the cap-heads f flush ,-with the inner ends of said heads. The dou-.

ble thickness afforded by the cap and body of the tubes securely holds the ducts and prevents leakage. These ducts are preferably Each tube 0 C is connected by horizontal ducts k with the adjacent central tube D. One of the end tubes D is tapped at p by a pipe with which the supply m joins. A vertical pipe q is connected by a eouplin g r with the pipe p and is provided with a trap s at its lower end. A pipe ttaps the pipe q and passes inthrough the firebox A over the grate and into one of the tubes D, as shown in Fig. 4. The gage .T is on the upper end of the pipe g, which is continued laterally at 16, passing over the series of tubes 0 and into the top of one of the central tubes D at r. (See Fig. 2.) Steam is taken from the domes of the pipes D by a pipe w, and another pipe 03 connects with a whistle or other use.

Surrounding the boiler outside the casing there is a pipe K, which may be covered with asbestos or other non-conductor or may be inclosed within the casing, if deemed prefer able. This circulation-pipe K is connected by horizontal ducts y, with each tube C C and at the front of the boiler by means of a duct .2 with the adjacent tube I) at the bottorn. The pipe has a trap 15 pendent therefrom. This pipe K, I- find by being arranged near the bottom of the vertical tubes and opening therein in manner described greatly facilitates the circulation and adds essentially to the cleanliness of the tubes, the lower caps being continually flushed by the circulation.

Tubes arranged as described present an extraordinary large heating-surface to the action of the fire and the steam generated in the top of the central tube is unusually dry. The cap-heads, being welded or screwed onto the tubes, reinforce the parts, enabling very light material to be employed.

Cold water taken in constantly at the supply end is driven through the connection a" by the hot water from the adjacent central tube D and is delivered into the boiler over the fire-box in a heated condition, which does not reduce the temperature within the tubes. This tends to save considerable fuel, and the direct circulation through the pipe K also effects this.

Having thus explained my invention, what I claim is 1. In a boiler a series of vertical tubes disposed over the firebox; a series of shorter tubes respectively on each side of said first series and connected therewith by horizontal circulation ducts and a pipe surrounding said tubes adjacent the fire box, said pipe being connected independently with each tube of the outer series and with one tube of the central series, substantially as described.

2. In a boiler, two series of parallel vertically arranged circulation tubes having their heads connected by flues; a central series of elongated tubes; horizontal ducts connecting the tubes of the central series and with each tube of the outer series respectively; a pipe surrounding said tubes adjacent the fire-box and connected by duets with each tube of the outer series and with one of the central series, all being arranged to operate substantially as described.

3. The fire-box in combination with the tubes, D, connected by ducts, the tubes, 0, C connected respectively with the tubes, D, by ducts; the pipe, K; the ducts, g, connect ing said pipe with the pipes, O, 0 and the duct, .2, connecting said pipe with a tube, D, all being arranged to operate substantially as described.

L. The tubes, D, O, 0 arranged and connected substantially as specified in combination with the pipe, K, disposed outside the casing and connecting with each tube, C, C and one tube, D, and the supply and discharge for said tube all being arranged to operate as described.

LElVIS SAUNDERS.

Vitnesses:

K. DURFEE, O. M. SHAW. 

